The present invention relates to an image forming apparatus and, more particularly, to an induction heating fixing device which uses an induction heating means as a heating source, and an image forming apparatus using the fixing device.
A fixing device which is related to the present invention uses a halogen lamp or the like as a heating source. The lamp is arranged inside a heat roller to heat it. A press roller is pressed against the heat roller and rotated so as to bring the print medium into press contact with the heat roller, and a paper sheet is passed between the two rollers.
FIG. 8 shows a schematic structure of the overall fixing device. A halogen lamp 102 is arranged inside a thin, metal heat roller 101. An elastic member is formed on the surface of a press roller 103 to make the print medium in sufficient press contact with the heat roller 101. The heat roller 101 and press roller 103 are supported while being applied with a predetermined pressure by a compression mechanism (not shown). Furthermore, the heat roller 101 and press roller 103 are rotated by a drive source (not shown) in the directions of arrows at the same speed as the convey speed of the print medium.
The fixing device using the halogen lamp 102 suffers poor thermal efficiency, and it is hard to reduce consumption power. Also, a long warm-up time is required from when the power supply is turned on until the heat roller 101 reaches the temperature required for fixing operation.